Problem: Khan.scratchpad.disable(); For every level Stephanie completes in her favorite game, she earns $520$ points. Stephanie already has $180$ points in the game and wants to end up with at least $2220$ points before she goes to bed. What is the minimum number of complete levels that Stephanie needs to complete to reach her goal?
Solution: To solve this, let's set up an expression to show how many points Stephanie will have after each level. Number of points $=$ $ $ Levels completed $\times$ Points per level $+$ Starting points Since Stephanie wants to have at least $2220$ points before going to bed, we can set up an inequality. Number of points $\geq 2220$ Levels completed $\times$ Points per level $+$ Starting points $\geq 2220$ We are solving for the number of levels to be completed, so let the number of levels be represented by the variable $x$ We can now plug in: $x \cdot 520 + 180 \geq 2220$ $ x \cdot 520 \geq 2220 - 180 $ $ x \cdot 520 \geq 2040 $ $x \geq \dfrac{2040}{520} \approx 3.92$ Since Stephanie won't get points unless she completes the entire level, we round $3.92$ up to $4$ Stephanie must complete at least 4 levels.